Replacing a timber member with steel is a design change, not a like-for-like substitution based on depth. The former generic equivalent-size recommendations here have been withdrawn.
Identify why replacement is proposed
Tell the engineer whether the issue is an altered layout, damage, movement or a change of loading. Record what is known about the timber, its supports and adjoining construction. If damage is involved, investigate its cause rather than assuming a stronger-looking member alone solves it.
Detail the interfaces
The replacement needs suitable supports, connections to remaining timber or masonry, restraint and relevant fire and moisture protection. Check available clearance and how the finished floor or ceiling will meet the new member. These interfaces may govern the practical arrangement.
Plan the temporary condition
Agree how the existing construction will be supported while work occurs, with responsibilities identified under the project plan. See HSE temporary-works guidance.
Our steel calculator methodology applies only to the stated UB model. It does not analyse timber damage, mixed-material connections or a replacement sequence. Use SCI’s steel-timber guidance as technical context alongside a project-specific design.
Structural work requires a chartered structural engineer and the applicable Building Control approval. This educational content has not received an independent engineering review.